Apparatus for radiative wireless power transmission and wireless power reception

ABSTRACT

Provided is an apparatus that may control a direction of wireless power transmission. A radiative wireless power transmitter may include at least two first unit resonators to form a magnetic field with a target resonator based on an x-axis direction and a z-axis direction, and to transmit a resonance power to the target resonator, at least two second unit resonators to form a magnetic field with the target resonator based on the x-axis direction and a y-axis direction, and to transmit a resonance power to the target resonator, at least two third unit resonators to form a magnetic field with the target resonator based on the y-axis direction and the z-axis direction, and to transmit a resonance power to the target resonator, and a feeding unit to control resonance power transmission of the at least two first unit resonators, the at least two second unit resonators, and the at least two

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. patent application Ser. No.13/178,100 filed on Jul. 7, 2011, which claims the benefit under 35U.S.C. §119(a) of Korean Patent Application No. 10-2010-0082110, filedon Aug. 24, 2010, in the Korean Intellectual Property Office, the entiredisclosures of which are incorporated herein by reference for allpurposes.

BACKGROUND

1. Field

The following description relates to an apparatus that may control adirection of wireless power transmission and wireless power reception.

2. Description of Related Art

Demand for electric devices including portable devices has rapidlyincreased. Typically, portable electric devices are supplied power via awired power supply, which can be inconvenient to a user. Studies onwireless power transmission have been conducted to overcome theinconvenience in wired power supply and a limited capacity of aconventional battery.

One example of wireless power transmission scheme uses a characteristicof resonance of radio frequency (RF) devices. A wireless powertransmission system based on the characteristic of resonance may includea source that supplies the power and a target that receives the power.An efficiency of the power transmission may vary based on whether thesource and the target are placed in parallel or in orthogonal.Accordingly, in a multi-device system, an efficiency of powertransmission of each device may be different based on a location and adirection of a corresponding device.

SUMMARY

A radiative wireless power transmitter, including at least two firstunit resonators to form a magnetic field with a target resonator basedon an x-axis direction and a z-axis direction, and to transmit aresonance power to the target resonator, at least two second unitresonators to form a magnetic field with the target resonator based onthe x-axis direction and a y-axis direction, and to transmit a resonancepower to the target resonator, at least two third unit resonators toform a magnetic field with the target resonator based on the y-axisdirection and the z-axis direction, and to transmit a resonance power tothe target resonator, and a feeding unit to control resonance powertransmission of the at least two first unit resonators, the at least twosecond unit resonators, and the at least two third unit resonators.

The feeding unit may comprise a first matcher that is placed in a planethat is parallel with the at least two first unit resonators and thatenables the at least two first unit resonators to form the magneticfield with the target resonator, a second matcher that is placed in aplane that is parallel with at least two second unit resonators and thatenables the at least two second unit resonators to form the magneticfield with the target resonator, and a third matcher that is placed inparallel with the at least two third unit resonators and that enablesthe at least two third unit resonators to form the magnetic field withthe target resonator.

The feeding unit may control a predetermined matcher from among thefirst matcher, the second matcher, and the third matcher, to enablewireless power transmission to be performed in a predetermineddirection.

The at least two first unit resonators, the at least two second unitresonators, and the at least two third unit resonators may each comprisea transmission line that comprises a first signal conducting portion, asecond signal conducting portion, and a ground conducting portioncorresponding to the first signal conducting portion and the secondsignal conducting portion, a first conductor that is electricallyconnected to the first signal conducting portion and the groundconducting portion, a second conductor that is electrically connected tothe second signal conducting portion and the ground conducting portion,and at least one capacitor inserted between the first signal conductingportion and the second signal conducting portion in series with respectto a current flowing through the first signal conducting porting and thesecond signal conducting portion.

The radiative wireless power transmitter may further comprise acontroller to generate a control signal to control the resonance powertransmission of the at least two first unit resonators, the at least twosecond unit resonators, and the at least two third unit resonators, andto generate a control signal to control impedances of the at least twofirst unit resonators, the at least two second unit resonators, and theat least two third unit resonators.

The at least two first unit resonators, the at least two second unitresonators, and the at least two third unit resonators may each be inthe shape of a square, and the at least two first unit resonators, theat least two second unit resonators, and the at least two third unitresonators may be connected with each other to form a shape of ahexahedron.

The first matcher, the second matcher, and the third matcher may each bein the shape of a square.

In another aspect, there is provided a radiative wireless powertransmitter, including a first unit resonator that is placed in a planethat is parallel to a direction of an x-axis and a z-axis, forming amagnetic field with a target resonator, and transmitting resonance powerto the target resonator, a second unit resonator that is placed in aplane that is parallel to a direction of the x-axis and a y-axis,forming a magnetic field with the target resonator, and transmittingresonance power to the target resonator, a third unit resonator that isplaced in a plane that is parallel to a direction of the y-axis and thez-axis, forming a magnetic field with the target resonator, andtransmitting resonance power to the target resonator, and a feeding unitto control resonance power transmission of the first unit resonator, thesecond unit resonator, and the third unit resonator.

The feeding unit may comprise a first matcher included in the first unitresonator and configured to enable the first unit resonator to form themagnetic field with the target resonator, a second matcher included inthe second unit resonator and configured to enable the second unitresonator to form the magnetic field with the target resonator, and athird matcher included in the third unit resonator and configured toenable the third unit resonators to form the magnetic field with thetarget resonator.

The feeding unit may control a predetermined matcher from among thefirst matcher, the second matcher, and the third matcher, to enablewireless power transmission to be performed in a predetermineddirection.

Each of the first unit resonator, the second unit resonator, and thethird unit resonator may be in the shape of a circle, and the first unitresonator, the second unit resonator, and the third unit resonator maybe connected with each other to form a shape of a sphere.

Each of the first matcher, the second matcher, and the third matcher maybe in the shape of a circle.

The radiative wireless power transmitter may further comprise acontroller to generate a control signal to control the resonance powertransmission of the first unit resonator, the second unit resonator, andthe third unit resonator, and to generate a control signal to controlimpedances of the first unit resonator, the second unit resonator, andthe third unit resonator.

In another aspect, there is provided a radiative wireless powerreceiver, including at least two first unit resonators to form amagnetic field with a source resonator based on an x-axis direction andz-axis direction, and to receive resonance power from the sourceresonator, at least two second unit resonators to form a magnetic fieldwith the source resonator based on the x-axis direction and a y-axisdirection, and to receive resonance power from the source resonator, atleast two third unit resonators to form a magnetic field with the sourceresonator based on the y-axis direction and the z-axis direction, and toreceive resonance power from the source resonator, and a feeding unit tocontrol resonance power reception of the at least two first unitresonators, the at least two second unit resonators, and the at leasttwo third unit resonators.

The feeding unit may control a predetermined matcher from among thefirst matcher, the second matcher, and the third matcher, to enablewireless power reception to be performed in a predetermined direction.

The radiative wireless power receiver may further comprise a detector todetect at least one of a distance between a wireless power transmissionresonator and a wireless power reception resonator, a reflectioncoefficient of a wave emitted from the wireless power transmissionresonator to the wireless power reception resonator, a powertransmission gain between the wireless power transmission resonator andthe wireless power reception resonator, and a coupling efficiency.

In another aspect, there is provided a radiative wireless powerreceiver, including a first unit resonator that is placed in a planethat is parallel to a direction of an x-axis and a z-axis, forming amagnetic field with a source resonator, and receiving resonance powerfrom the source resonator, a second unit resonator that is placed in aplane that is parallel to a direction of the x-axis and a y-axis,forming a magnetic field with the source resonator, and receivingresonance power from the source resonator, a third unit resonator thatis placed in a plane that is parallel to a direction of the y-axis andthe z-axis, forming a magnetic field with the source resonator, andreceiving resonance power from the source resonator, and a feeding unitto control resonance power reception of the first unit resonator, thesecond unit resonator, and the third unit resonator.

In another aspect, there is provided a resonator for wireless powertransmission, the resonator including a first resonating unit positionedin an XZ plane and configured to transmit/receive power wirelessly in adirection that is vertical to the XZ plane and that is parallel to they-axis, a second resonating unit positioned in an XY plane andconfigured to transmit/receive power wirelessly in a direction that isvertical to the XY plane and that is parallel to the z-axis, and a firstresonating unit positioned in a YZ plane and configured totransmit/receive power wirelessly in a direction that is vertical to theYZ plane and that is parallel to the y-axis.

The resonator may further comprise a first matcher that is positioned inthe XZ plane along a transmission path of the first resonating unit, asecond matcher that is positioned in the XY plane along a transmissionpath of the second resonating unit, and a third matcher that ispositioned in the YZ plane along a transmission path of the thirdresonating unit, wherein the first matcher, the second matcher, and thethird matcher control a respective resonating unit to enable therespective resonating unit to perform magnetic coupling with a targetdevice.

Other features and aspects may be apparent from the following detaileddescription, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a wireless powertransmission system.

FIG. 2 is a diagram illustrating an example of a radiative wirelesspower transmitter and receiver.

FIGS. 3A and 3B are diagrams illustrating additional examples of aradiative wireless power transmitter and receiver.

FIG. 4 is a diagram illustrating an example of a wireless powertransmitter.

FIG. 5 is a diagram illustrating an example of a wireless powerreceiver.

FIG. 6 is a diagram illustrating a two-dimensional (2D) example of aresonator.

FIG. 7 is a diagram illustrating a three-dimensional (3D) example of aresonator.

FIG. 8 is a diagram illustrating an example of a resonator for wirelesspower transmission configured as a bulky type.

FIG. 9 is a diagram illustrating an example of a resonator for wirelesspower transmission configured as hollow type.

FIG. 10 is a diagram illustrating an example of a resonator for wirelesspower transmission using a parallel-sheet.

FIG. 11 is a diagram illustrating an example of a resonator for wirelesspower transmission including a distributed capacitor.

FIG. 12A is a diagram illustrating an example of a matcher used by theresonator of FIG. 6.

FIG. 12B is a diagram illustrating an example of a matcher used by theresonator of FIG. 7.

FIG. 13 is a diagram illustrating an example of an equivalent circuit ofthe resonator for wireless power transmission of FIG. 6.

Throughout the drawings and the detailed description, unless otherwisedescribed, the same drawing reference numerals should be understood torefer to the same elements, features, and structures. The relative sizeand depiction of these elements may be exaggerated for clarity,illustration, and convenience.

DETAILED DESCRIPTION

The following detailed description is provided to assist the reader ingaining a comprehensive understanding of the methods, apparatuses,and/or systems described herein. Accordingly, various changes,modifications, and equivalents of the methods, apparatuses, and/orsystems described herein may be suggested to those of ordinary skill inthe art. Also, descriptions of well-known functions and constructionsmay be omitted for increased clarity and conciseness.

The following description is related to a wireless power transmissiontechnology that may be used by a wireless power transmission system. Thewireless power transmission technology may be classified into aplurality of schemes, for example, an electromagnetic induction scheme,a radio wave reception scheme, a resonance scheme, and the like.

For example, in the electromagnetic induction scheme, if two coils areclose enough to each other, and an alternating current is flowingthrough one of the coils, a magnetic flux may be generated and anelectromotive force may be induced in the other coil. Theelectromagnetic induction scheme may be based on the above-describedphenomenon. For purposes of example, the electromagnetic inductionscheme may have approximately 60% to 98% efficiency in using power. As aresult, the electromagnetic induction is relatively efficient andpractical.

As another example, in the radio wave reception scheme radio wave energymay be received via an antenna and may obtain power by converting awaveform of alternating radio waves into direct current (DC), forexample, using a rectifier circuit. For example, the radio wavereception scheme may perform wireless power transmission over severalmeters.

As another example, the resonance scheme may be based on a resonance ofan electric field or a magnetic field. The resonance scheme may transmitenergy between devices, wherein the transmission of energy is resonatedat the same frequency. For example, if the resonance of the magneticfield is used, which is referred to as a magnetic resonance scheme,power may be generated through a magnetic resonance coupling thatutilizes a structure of an LC resonator.

The magnetic resonance scheme may use a near field effect over arelatively short distance as compared with a wavelength of a usedfrequency. In this example, the magnetic resonance scheme may be anon-radiative energy transmission that is different from the radio wavereception scheme. The magnetic resonance scheme may match resonancefrequencies of a transmitter and a receiver to transmit power. Forpurpose of example, the efficiency of the magnetic resonance scheme inusing power may increase by approximately 50% to 60%, which isrelatively higher than the radio wave reception scheme emitting anelectromagnetic wave.

For example, the distance between the transmitter and the receiver ofthe magnetic resonance scheme may be about several meters, which is arelatively closer distance as compared with the radio wave receptionscheme. However, the magnetic resonance scheme may be capable oftransmitting power over a relatively long distance as compared with theelectromagnetic induction scheme.

As described herein, for example, the source or transmitter may be, ormay be included in, a terminal, such as a mobile terminal, a personalcomputer, a personal digital assistant (PDA), an MP3 player, and thelike. As another example, the target or receiver described herein maybe, or may be included in, a terminal, such as a mobile terminal, apersonal computer, a personal digital assistant (PDA), an MP3 player,and the like. As another example, the transmitter and/or the receivermay be a separate individual unit.

FIG. 1 illustrates an example of a wireless power transmission system.

As described herein, a wireless power transmitted using the wirelesspower transmission system may be referred to as resonance power.

Referring to FIG. 1, the wireless power transmission system includes asource-target structure including a source and a target. In thisexample, the wireless power transmission system includes a resonancepower transmitter 110 corresponding to the source and a resonance powerreceiver 120 corresponding to the target.

The resonance power transmitter 110 includes a source unit 111 and asource resonator 115. The source unit 111 may receive energy from anexternal voltage supplier to generate a resonance power. The resonancepower transmitter 110 may further include a matching control 113 toperform resonance frequency or impedance matching.

For example, the source unit 111 may include an alternating current(AC)-to-AC (AC/AC) converter, an AC-to-direct current (DC) (AC/DC)converter, a (DC/AC) inverter, and the like. The AC/AC converter mayadjust, to a desired level, a signal level of an AC signal input from anexternal device. The AC/DC converter may output a DC voltage at apredetermined level by rectifying an AC signal output from the AC/ACconverter. The DC/AC inverter may generate an AC signal of, for example,a few megahertz (MHz) to tens of MHz band by quickly switching a DCvoltage output from the AC/DC converter.

The matching control 113 may set at least one of a resonance bandwidthof the source resonator 115 and an impedance matching frequency of thesource resonator 115. Although not illustrated in FIG. 1, the matchingcontrol 113 may include at least one of a source resonance bandwidthsetting unit and a source matching frequency setting unit. The sourceresonance bandwidth setting unit may set the resonance bandwidth of thesource resonator 115. The source matching frequency setting unit may setthe impedance matching frequency of the source resonator 115. Forexample, a Q-factor of the source resonator 115 may be determined basedon the setting of the resonance bandwidth of the source resonator 115and/or the setting of the impedance matching frequency of the sourceresonator 115.

The source resonator 115 may transfer electromagnetic energy to a targetresonator 121. For example, the source resonator 115 may transferresonance power to the resonance power receiver 120 through magneticcoupling 101 with the target resonator 121. The source resonator 115 mayresonate within the set resonance bandwidth.

In this example, the resonance power receiver 120 includes the targetresonator 121, a matching control 123 to perform resonance frequency orimpedance matching, and a target unit 125 to transfer the receivedresonance power to a load.

The target resonator 121 may receive the electromagnetic energy from thesource resonator 115. The target resonator 121 may resonate within theset resonance bandwidth.

The matching control 123 may set at least one of a resonance bandwidthof the target resonator 121 and an impedance matching frequency of thetarget resonator 121. Although not illustrated in FIG. 1, the matchingcontrol 123 may include at least one of a target resonance bandwidthsetting unit and a target matching frequency setting unit. The targetresonance bandwidth setting unit may set the resonance bandwidth of thetarget resonator 121. The target matching frequency setting unit may setthe impedance matching frequency of the target resonator 121. Forexample, a Q-factor of the target resonator 121 may be determined basedon the setting of the resonance bandwidth of the target resonator 121and/or the setting of the impedance matching frequency of the targetresonator 121.

The target unit 125 may transfer the received resonance power to theload. For example, the target unit 125 may include an AC/DC converterand a DC/DC converter. The AC/DC converter may generate a DC voltage byrectifying an AC signal transmitted from the source resonator 115 to thetarget resonator 121. The DC/DC converter may supply a rated voltage toa device or the load by adjusting a voltage level of the DC voltage.

For example, the source resonator 115 and the target resonator 121 maybe configured in a helix coil structured resonator, a spiral coilstructured resonator, a meta-structured resonator, and the like.

Referring to FIG. 1, a process of controlling the Q-factor may includesetting the resonance bandwidth of the source resonator 115 and theresonance bandwidth of the target resonator 121, and transferring theelectromagnetic energy from the source resonator 115 to the targetresonator 121 through magnetic coupling 101 between the source resonator115 and the target resonator 121. For example, the resonance bandwidthof the source resonator 115 may be set wider or narrower than theresonance bandwidth of the target resonator 121. For example, anunbalanced relationship between a bandwidth (BW)-factor of the sourceresonator 115 and a BW-factor of the target resonator 121 may bemaintained by setting the resonance bandwidth of the source resonator115 to be wider or narrower than the resonance bandwidth of the targetresonator 121.

In a wireless power transmission system employing a resonance scheme,the resonance bandwidth may be an important factor. When the Q-factorconsidering all of a change in a distance between the source resonator115 and the target resonator 121, a change in the resonance impedance,impedance mismatching, a reflected signal, and the like, is Qt, Qt mayhave an inverse-proportional relationship with the resonance bandwidth,as given by Equation 1.

$\begin{matrix}\begin{matrix}{\frac{\Delta \; f}{f_{0}} = \frac{1}{Qt}} \\{= {\Gamma_{S,D} + \frac{1}{{BW}_{S}} + \frac{1}{{BW}_{D}}}}\end{matrix} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

In Equation 1, f₀ denotes a central frequency, Δf denotes a change in abandwidth, T_(S,D) denotes a reflection loss between the sourceresonator 115 and the target resonator 121, BW_(S) denotes the resonancebandwidth of the source resonator 115, and BW_(D) denotes the resonancebandwidth of the target resonator 121. For example, the BW-factor mayindicate either 1/BW_(S) or 1/BW_(D).

Due to an external effect, impedance mismatching between the sourceresonator 115 and the target resonator 121 may occur. For example, achange in the distance between the source resonator 115 and the targetresonator 121, a change in a location of at least one of the sourceresonator 115 and the target resonator 121, and the like, may causeimpedance mismatching between the source resonator 115 and the targetresonator 121 to occur. The impedance mismatching may be a direct causein decreasing an efficiency of power transfer. When a reflected wavecorresponding to a transmission signal that is partially reflected bythe source and returned towards the target is detected, the matchingcontrol 113 may determine that impedance mismatching has occurred, andmay perform impedance matching. For example, the matching control 113may change a resonance frequency by detecting a resonance point througha waveform analysis of the reflected wave. The matching control 113 maydetermine, as the resonance frequency, a frequency that has a minimumamplitude in the waveform of the reflected wave.

For example, a resonator may be configured as a helix coil structuredresonator, a spiral coil structured resonator, a meta-structuredresonator, and the like.

All materials may have a unique magnetic permeability (MO and a uniquepermittivity epsilon (e). The magnetic permeability indicates a ratiobetween a magnetic flux density that occurs with respect to a givenmagnetic field in a corresponding material and a magnetic flux densitythat occurs with respect to the given magnetic field in a vacuum state.The magnetic permeability and the permittivity may determine apropagation constant of a corresponding material at a given frequency orat a given wavelength. An electromagnetic characteristic of thecorresponding material may be determined based on the magneticpermeability and the permittivity.

For example, a material having a magnetic permeability or a permittivityabsent in nature and artificially designed may be referred to as ametamaterial. The metamaterial may be easily disposed in a resonancestate even in a relatively large wavelength area or a relatively lowfrequency area. For example, even though a material size rarely varies,the metamaterial may be easily disposed in the resonance state.

FIG. 2 illustrates an example of a radiative wireless power transmitterand receiver.

A unit resonator may be in the form of an electrically closed loop. Forexample, the loop structure may include a circle, a polygon such as asquare, and the like. A primary direction of a magnetic field may beformed to be vertical to a plane of the unit resonator. In wirelesspower transmission using a near field, a magnetic field in a verticaldirection may occupy most of the formed magnetic field. Therefore, whena source resonator and a target resonator are orthogonal to each other,wireless power transmission may not be performed. In an environment inwhich the wireless power transmission is performed, the source resonatorand the target resonator may be placed in an arbitrary direction to eachother. The source resonator may perform wireless power transmissionthrough resonating, with respect to the corresponding target resonator.

Referring to FIG. 2, the radiative wireless power transmitter andreceiver includes first unit resonators 210, second unit resonators 220,third unit resonators 230, and a feeding unit 240.

For example, the first unit resonators 210 may form a magnetic fieldwith a target resonator based on an x-axis direction and z-axisdirection or XZ plane. The forming of the magnetic field with the targetresonator based on the x-axis direction and z-axis direction indicates amagnetic field that is formed in parallel to the y-axis. The first unitresonators 210 may transmit resonance power to the target resonatorthrough the magnetic field. In this example, the first unit resonators210 may transmit power in a direction that is vertical to the XZ planeand that is parallel to the y-axis. In the radiative wireless powerreceiver, the first unit resonators 210 may form a magnetic field with asource resonator based on the direction of the x-axis and z-axis. Thefirst unit resonators 210 may receive resonance power from the sourceresonator through the magnetic field. For example, the first unitresonators 210 may include at least two unit resonators that areparallel with the XZ plane.

As another example, the second unit resonators 220 may form a magneticfield with the target resonator based on an x-axis direction and y-axisdirection or XY plane. The forming of the magnetic field with the targetresonator based on the x-axis direction and y-axis direction indicates amagnetic field that is formed vertical to the XY plane and that isparallel to the direction of the z-axis. The second unit resonators 220may transmit resonance power through the target resonator. In theradiative wireless power receiver, the second unit resonators 220 mayform a magnetic field with the source resonator based on the directionof the x-axis and y-axis. The second unit resonators 220 may receiveresonance power from the source resonator through the magnetic field.For example, the second unit resonators 220 may include at least twounit resonators that are parallel with the XY plane.

As another example, the third unit resonators 230 may form a magneticfield with the target resonator based on a y-axis direction and z-axisdirection or YZ plane. The forming of the magnetic field with the targetresonator based on the y-axis direction and z-axis direction indicates amagnetic field that is formed along a direction that is vertical to theYZ plane and that is parallel to the direction of the x-axis. The thirdunit resonators 230 may transmit resonance power to the target resonatorthrough the magnetic field. In the radiative wireless power receiver,the third unit resonators 230 may form a magnetic field with the sourceresonator based on the direction of the y-axis and z-axis. The thirdunit resonators 230 may receive resonance power from the sourceresonator through the magnetic field. For example, the third unitresonators 230 may include at least two unit resonators that areparallel with the plane of the y-axis and z-axis.

The first unit resonators 210, the second unit resonators 220, and thethird unit resonators 230 may be orthogonal to each other. In thisexample, the first unit resonators 210 may transmit power in a directionthat is parallel to the y-axis, the second unit resonators 220 maytransmit power in a direction that is parallel to the z-axis, and thethird unit resonators 230 may transmit power in a direction that isparallel to the x-axis.

As an example, the unit resonator included in the first unit resonators210, the second unit resonators 220, and the third unit resonators 230may be in a square structure, and the unit resonators may be connectedwith each other to form a structure of a hexahedron of FIG. 2. In thisexample, a source resonator of the hexahedron structure may transmitresonance power to a target resonator located at the top, the bottom,the left, the right, the fore, and the rear of the hexahedron structure.Accordingly, wireless power transmission efficiency of the sourceresonator may be maintained regardless of a location of a target deviceincluding the target resonator because the resonators are capable oftransmitting power in any direction from the wireless power transmitter.

The feeding unit 240 may control resonance power transmission that isperformed by the first unit resonators 210, the second unit resonators220, and the third unit resonators 230. For example, the feeding unit240 may control current flowing through the first unit resonators 210,the second unit resonators 220, and the third unit resonators 230 tocontrol the resonance power transmission. In the radiative wirelesspower receiver, the feeding unit 240 may control resonance powerreception that is performed by the first unit resonators 210, the secondunit resonators 220, and the third unit resonators 230. For example, thefeeding unit 240 may control the current flowing through the first unitresonators 210, the second unit resonators 220, and the third unitresonators 230 to control the resonance power reception.

In this example, the feeding unit 240 includes a first matcher 241, asecond matcher 243, and a third matcher 245. The first matcher 241 isplaced in the XZ plane that is parallel with the first unit resonators210. The first matcher 241 may enable the first unit resonators 210 toform a magnetic field with the target device. As another example, thefirst matcher 241 may enable the first unit resonators 210 to form amagnetic field with a source device.

In this example, the second matcher 243 is placed in the XY plane thatis parallel with the second unit resonators 220. The second matcher 243may enable the second unit resonators 230 to form a magnetic field withthe target device. As another example, the second matcher 243 may enablethe second unit resonators 220 to form a magnetic field with the sourcedevice.

In this example, the third matcher 245 is placed in the YZ plane that isparallel with the third unit resonators 230. The third matcher 245 mayenable the third unit resonators 230 to form a magnetic device with thetarget device. As another example, the third matcher 245 may enable thethird unit resonators 230 to form a magnetic field with the sourcedevice. In this example, the target device may include the targetresonator and the source device may include the source resonator.

The feeding unit 240 may operate one of the first matcher 241, thesecond matcher 243, and the third matcher 245 to enable unit resonatorsthat are placed in a plane parallel with each matcher to form a magneticfield. For example, the feeding unit 240 may operate a predeterminedmatcher to enable a unit resonator in a predetermined direction to forma magnetic field. Accordingly, wireless power transmission and wirelesspower reception may be performed in the predetermined direction.

Each matcher may perform magnetic coupling with a unit resonator that isplaced in a plane parallel to a corresponding matcher. As a result, thematcher may enable the unit resonator to transmit or receive resonancepower. The matcher may be configured as a resonance structure that isable to perform magnetic coupling. The matcher may control currentflowing through the unit resonator that is placed in parallel with thematcher, and thus, may control the resonance power that is transmittedand/or received by the unit resonator.

Each of the first matcher 241, the second matcher 243, and the thirdmatcher 245 may be a square structure. For example, each matcher mayhave the same shape as the unit resonator that is placed in a planeparallel to a corresponding matcher. The matcher may control resonancepower transmission of the corresponding unit resonator through magneticcoupling, and an efficiency of the resonance power transmission mayincrease.

FIGS. 3A and 3B illustrate additional examples of a radiative wirelesspower transmitter and receiver.

In this example, the radiative wireless power transmitter and theradiative wireless power receiver include a first unit resonator, forexample, first unit resonators 320 and 360, a second unit resonator, forexample, second unit resonators 330 and 370, a third unit resonator, forexample, third unit resonators 310 and 350, and a feeding unit, forexample, feeding units 340 and 380.

In the radiative wireless power transmitter, the first unit resonators320 and 360 are placed in parallel to a plane along the x-axis and thez-axis (XZ plane) and may form a magnetic field with a target resonator.The first unit resonators 320 and 360 may transmit resonance power tothe target resonator through a magnetic field. In the radiative wirelesspower receiver, the first unit resonators 320 and 360 are placed inparallel to the XZ plane and may form a magnetic field with a sourceresonator. In this example, the magnetic field formed by the first unitresonators 320 and 360 is formed vertical to the XZ plane and along adirection that is parallel to the y-axis. The first unit resonator mayreceive resonance power from the source resonator through the magneticfield.

In the radiative wireless power transmitter, the second unit resonators330 and 370 are placed in parallel to the plane along the x-axis and they-axis (XY plane) and may form a magnetic field with the targetresonator. The second unit resonators 330 and 370 may transmit resonancepower to the target resonator through the magnetic field. In theradiative wireless power receiver, the second unit resonators 330 and370 are placed in parallel to the XY plane and may form a magnetic fieldwith the source resonator. In this example, the magnetic field formed bythe second unit resonators 330 and 370 is formed vertical to the XYplane and along a direction that is parallel to the z-axis. The secondunit resonator may receive resonance power from the source resonatorthrough the magnetic field.

In the radiative wireless power transmitter, the third unit resonators310 and 350 are placed in parallel to a plane along the y-axis and thez-axis (YZ plane) and may form a magnetic field with the targetresonator. The third unit resonators 310 and 350 may transmit resonancepower to the target resonator through the magnetic field. In theradiative wireless power receiver, the third unit resonators 310 and 350are placed in parallel to the YZ plane and may form a magnetic fieldwith the source resonator. In this example, the magnetic field formed bythe third unit resonators 310 and 350 is formed vertical to the YZ planeand along a direction that is parallel to the x-axis. The third unitresonator may receive resonance power from the source resonator throughthe magnetic field.

The first unit resonators 320 and 360, the second unit resonators 330and 370, and the third unit resonators 310 and 350 may be orthogonal toeach other. In this example, the first unit resonators 320 and 360 maytransmit power in a direction that is parallel to the y-axis, the secondunit resonators 330 and 370 may transmit power in a direction that isparallel to the z-axis, and the third unit resonators 310 and 350 maytransmit power in a direction that is parallel to the x-axis.

The first unit resonators 320 and 360, the second unit resonators 330and 370, and the third unit resonators 310 and 350 may be in a structureof a polygon, respectively. Therefore, a unit resonator may beconfigured in a structure of a square or a circle. The source resonatorin a polygon structure may transmit resonance power through magneticcoupling with a target resonator that is facing each unit resonator ofthe polygon structure. In this example, the efficiency of wireless powertransmission of the source resonator may be maintained within apredetermined range, regardless of a location of a target deviceincluding the target resonator. In this example, the polygon structuremay be a simpler structure than the hexahedron structure of FIG. 2, mayperform the same function as the hexagon structure, and may maintain theefficiency of the wireless power transmission and reception.

In the radiative wireless power transmitter, the feeding units 340 and380 may control the resonance power transmission performed by the firstunit resonators 320 and 360, the second unit resonators 330 and 370, andthe third unit resonators 310 and 350, respectively. The feeding units340 and 380 may control current that flows through by the first unitresonators 320 and 360, the second unit resonators 330 and 370, and thethird unit resonators 310 and 350, and thus, may control the resonancepower transmission.

Also, in the radiative wireless power receiver, the feeding units 340and 380 may control the resonance power reception performed by the firstunit resonators 320 and 360, the second unit resonators 330 and 370, andthe third unit resonators 310 and 350, respectively. The feeding units340 and 380 may control current that flows through the first unitresonators 320 and 360, the second unit resonators 330 and 370, and thethird unit resonators 310 and 350, and thus, may control the resonancepower reception.

In this example, each of the feeding units 340 and 380, includes a firstmatcher, for example, first matchers 343 and 383, a second matcher, forexample, second matchers 345 and 385, and a third matcher, for example,third matchers 341 and 381. The first matchers 343 and 383 may belocated within the first unit resonators 320 and 360. In this example,the first matchers 343 and 383 are placed in the XZ plane that isparallel with the first unit resonator 320 and 360, respectively. Thefirst matchers 343 and 383 may enable the first unit resonators 320 and360 to form a magnetic field with the target device. The first matchers343 and 383 may enable the first unit resonators 320 and 360 to form amagnetic field with the source device.

The second matchers 345 and 385 may be located within the second unitresonators 330 and 370. In this example, the second matchers 345 and 385are placed in the XY plane that is parallel with the second unitresonators 330 and 370, respectively. The second matchers 345 and 385may enable the second unit resonators 330 and 370 to form a magneticfield with the target device. The second matchers 345 and 385 may enablethe second unit resonators 330 and 370 to form a magnetic field with thesource device.

The third matchers 341 and 381 may be located within the third unitresonator 310 and 350. In this example, the third matchers 341 and 381are placed in the YZ plane that is parallel with the third unitresonators 310 and 350, respectively. The third matchers 341 and 381 mayenable the third unit resonators 310 and 350 to form a magnetic fieldwith the target device. The third matchers 341 and 381 may enable thethird unit resonators 310 and 350 to form a magnetic field with thesource device.

The feeding units 340 and 380 may operate one of the first matcher 343and 383, the second matcher 345 and 385, and the third matcher 341 and381 to enable a unit resonator that is placed in a plane that isparallel with each matcher to form a magnetic field. In this example,the feeding units 340 and 380 may only operate a predetermined matcherto enable a unit resonator in a predetermined direction to form amagnetic field, and thus, wireless power transmission or reception maybe performed in the predetermined direction.

Each matcher may perform magnetic coupling with a unit resonator that isplaced in a plane that is parallel with a corresponding matcher, andthus, may enable the unit resonator to transmit or to receive resonancepower. For example, the matcher may be configured as a resonancestructure that is able to perform magnetic coupling. The matcher maycontrol current that flows through the unit resonator placed in a planethat is parallel with the matcher, and thus, may control the resonancepower transmitted or received by the unit resonator.

Each of the first matcher 343, the second matcher 345, and the thirdmatcher 341 may be in a structure of a circle. Each matcher may beconfigured to have the same shape as a unit resonator placed in a planethat is parallel to a corresponding matcher. In this example, thematcher may control resonance power transmission of the correspondingunit resonator through magnetic coupling, and an efficiency of resonancepower transmission may increase.

FIG. 4 illustrates an example of a wireless power transmitter that isapplicable to the source of FIG. 1.

Referring to FIG. 4, the wireless power transmitter 400 includes awireless power transmission resonator 410 and a pre-processor 420.

The wireless power transmission resonator 410 may be a resonator such asthe example resonators described with reference to FIGS. 2, 3A, 3B, and6 through 13, and power may be wirelessly transmitted by a wave that ispropagated by the wireless power transmission resonator 410.

The pre-processor 420 may generate a current and a frequency to be usedfor wireless power transmission using energy that is supplied from anexternal and/or an internal power supply.

In this example, the pre-processor 420 includes an AC/DC converter 421,a frequency generator 422, a power amplifier 423, a controller 424, anda detector 425.

The AC/DC converter 421 may convert AC energy that is supplied from thepower supply to DC energy or to a DC current. In this example, thefrequency generator 422 may generate a desired frequency, for example, adesired resonance frequency, based on the DC energy or the DC current,and may generate a current of the desired frequency. In this example,the current of the desired frequency may be amplified by the amplifier423.

The controller 424 may generate a control signal to control an impedanceof the wireless power transmission resonator 410, and may control afrequency that is generated by the frequency generator 422. For example,an optimal frequency that maximizes a power transmission gain, acoupling effect, and the like, may be selected from among multiplefrequency bands. The controller 424 may generate a control signal tocontrol a feeding unit 411. The feeding unit 411 may control resonancepower transmission of the wireless power transmission resonator 410. Thefeeding unit 411 may control current that flows through the wirelesspower transmission resonator 410 to control the resonance powertransmission. The feeding unit 411 may control the resonance powertransmission through magnetic coupling with the wireless powertransmission resonator 410.

The detector 425 may detect various features. For example, the detector425 may detect a distance between the wireless power transmissionresonator 410 and a wireless power reception resonator of a wirelesspower receiver, a reflection coefficient of a wave that is radiated fromthe wireless power transmission resonator 410 to the wireless powerreception resonator, a power transmission gain between the wirelesspower transmission resonator 410 and the wireless power receptionresonator, a coupling efficiency between the wireless power transmissionresonator 410 and the wireless power reception resonator, and the like.

In this example, the controller 424 may control the impedance of thewireless power transmission resonator 410 based on one or more of thedistance, the reflection coefficient, the power transmission gain, thecoupling efficiency, and the like, or may generate a control signal thatcontrols the frequency generated by the frequency generator 422 based onany of the distance, the reflection coefficient, the power transmissiongain, the coupling efficiency, and the like.

FIG. 5 illustrates an example of a wireless power receiver that isapplicable to the target of FIG. 1.

Referring to FIG. 5, the wireless power receiver 500 includes a wirelesspower reception resonator 510, a rectifier 520, a detector 530, and acontroller 540.

The wireless power reception resonator 510 may be a resonator asdescribed in the examples with reference to FIGS. 2, 3A, 3B, and 6through 13, and may receive a wave that is propagated by a wirelesspower transmitter.

The rectifier 520 may convert power that is carried through the receivedwave to DC energy, and some or all of the DC energy may be provided to atarget device.

The detector 530 may detect various features. For example, the detector530 may detect a distance between a wireless power transmissionresonator and the wireless power reception resonator 510 of the wirelesspower receiver 500, a reflection coefficient of a wave that is radiatedfrom the wireless power transmission resonator 410 to the wireless powerreception resonator 510, a power transmission gain between the wirelesspower transmission resonator 410 and the wireless power receptionresonator 510, a coupling efficiency between the wireless powertransmission resonator 410 and the wireless power reception resonator510, and the like.

The controller 540 may generate a control signal to control an impedanceof the wireless power reception resonator 510 based on one or more ofthe distance, the reflection coefficient, the power transmission gain,the coupling efficiency, and the like. The controller 540 may generate asignal to control a feeding unit 511. The feeding unit 511 may controlresonance power reception of the wireless power reception resonator 510.The feeding unit 511 may control current that flows through the wirelesspower reception resonator 510 to control the resonance power reception.The feeding unit 511 may control the resonance power reception throughmagnetic coupling with the wireless power reception resonator 510.

FIG. 6 illustrates a two-dimensional (2D) example of a resonator.

Referring to FIG. 6, resonator 600 includes a transmission line, acapacitor 620, a matcher 630, and conductors 641 and 642. In thisexample, the transmission line includes a first signal conductingportion 611, a second signal conducting portion 612, and a groundconducting portion 613.

The capacitor 620 may be inserted in series between the first signalconducting portion 611 and the second signal conducting portion 612, andan electric field may be confined within the capacitor 620. For example,the transmission line may include at least one conductor in an upperportion of the transmission line, and may also include at least oneconductor in a lower portion of the transmission line. Current may flowthrough the at least one conductor disposed in the upper portion of thetransmission line, and the at least one conductor disposed in the lowerportion of the transmission may be electrically grounded. In thisexample, a conductor disposed in an upper portion of the transmissionline is referred to as the first signal conducting portion 611 and thesecond signal conducting portion 612. A conductor disposed in the lowerportion of the transmission line is referred to as the ground conductingportion 613.

In this example, the transmission line includes the first signalconducting portion 611 and the second signal conducting portion 612 inthe upper portion of the transmission line, and includes the groundconducting portion 613 in the lower portion of the transmission line.For example, the first signal conducting portion 611 and the secondsignal conducting portion 612 may be disposed such that they face theground conducting portion 613. Current may flow through the first signalconducting portion 611 and the second signal conducting portion 612.

For example, one end of the first signal conducting portion 611 may beshorted to the conductor 642, and another end of the first signalconducting portion 611 may be connected to the capacitor 620. One end ofthe second signal conducting portion 612 may be grounded to theconductor 641, and another end of the second signal conducting portion612 may be connected to the capacitor 620. Accordingly, the first signalconducting portion 611, the second signal conducting portion 612, theground conducting portion 613, and the conductors 641 and 642 may beconnected to each other, and the resonator 600 may have an electricallyclosed-loop structure. The term “loop structure” may include a polygonalstructure, for example, a circular structure, a rectangular structure,and the like. In this example, “a loop structure” indicates a circuitthat is electrically closed.

The capacitor 620 may be inserted into an intermediate portion of thetransmission line. For example, the capacitor 620 may be inserted into aspace between the first signal conducting portion 611 and the secondsignal conducting portion 612. The capacitor 620 may have variousshapes, for example, a shape of a lumped element, a distributed element,and the like. For example, a distributed capacitor that has the shape ofthe distributed element may include zigzagged conductor lines and adielectric material that has a relatively high permittivity between thezigzagged conductor lines.

When the capacitor 620 is inserted into the transmission line, theresonator 600 may have a property of a metamaterial. The metamaterialindicates a material that has a predetermined electrical property thatis absent in nature and thus, may have an artificially designedstructure. An electromagnetic characteristic of materials that exist innature may have a unique magnetic permeability or a unique permittivity.Most materials may have a positive magnetic permeability or a positivepermittivity. In the case of most materials, a right hand rule may beapplied to an electric field, a magnetic field, and a pointing vectorand thus, the corresponding materials may be referred to as right handedmaterials (RHMs).

However, a metamaterial has a magnetic permeability or a permittivityabsent in nature, and thus, may be classified into, for example, anepsilon negative (ENG) material, a mu negative (MNG) material, a doublenegative (DNG) material, a negative refractive index (NRI) material, aleft-handed (LH) material, and the like, based on a sign of thecorresponding permittivity or magnetic permeability.

When a capacitance of the capacitor inserted as the lumped element isappropriately determined, the resonator 600 may have the characteristicof the metamaterial. Because the resonator 600 may have a negativemagnetic permeability by adjusting the capacitance of the capacitor 620,the resonator 600 may also be referred to as an MNG resonator. Variouscriteria may be applied to determine the capacitance of the capacitor620. For example, the various criteria may include a criterion forenabling the resonator 600 to have the characteristic of themetamaterial, a criterion for enabling the resonator 600 to have anegative magnetic permeability in a target frequency, a criterion forenabling the resonator 600 to have a zeroth order resonancecharacteristic in the target frequency, and the like. The capacitance ofthe capacitor 620 may be determined by at least one criterion.

The resonator 600, also referred to as the MNG resonator 600, may have azeroth order resonance characteristic that has, as a resonancefrequency, a frequency when a propagation constant is “0”. For example,a zeroth order resonance characteristic may be a frequency transmittedthrough a line or medium that has a propogation constant of zero.Because the resonator 600 may have the zeroth order resonancecharacteristic, the resonance frequency may be independent with respectto a physical size of the MNG resonator 600. By appropriately designingthe capacitor 620, the MNG resonator 600 may sufficiently change theresonance frequency. Accordingly, the physical size of the MNG resonator600 may not be changed.

In a near field, the electric field may be concentrated on the capacitor620 inserted into the transmission line. Accordingly, due to thecapacitor 620, the magnetic field may become dominant in the near field.The MNG resonator 600 may have a relatively high Q-factor using thecapacitor 620 of the lumped element and thus, it is possible to enhancean efficiency of power transmission. In this example, the Q-factorindicates a level of an ohmic loss or a ratio of a reactance withrespect to a resistance in the wireless power transmission. It should beunderstood that the efficiency of the wireless power transmission mayincrease according to an increase in the Q-factor.

The MNG resonator 600 may include the matcher 630 for impedancematching. The matcher 630 may adjust the strength of a magnetic field ofthe MNG resonator 600. An impedance of the MNG resonator 600 may bedetermined by the matcher 630. For example, current may flow into and/orout of the MNG resonator 600 via a connector. The connector may beconnected to the ground conducting portion 613 or the matcher 630. Powermay be transferred through coupling without using a physical connectionbetween the connector and the ground conducting portion 613 or thematcher 630.

For example, as shown in FIG. 6, the matcher 630 may be positionedwithin the loop formed by the loop structure of the resonator 600. Thematcher 630 may adjust the impedance of the resonator 600 by changingthe physical shape of the matcher 630. For example, the matcher 630 mayinclude the conductor 631 for the impedance matching in a location thatis separated from the ground conducting portion 613 by a distance h.Accordingly, the impedance of the resonator 600 may be changed byadjusting the distance h.

Although not illustrated in FIG. 6, a controller may be provided tocontrol the matcher 630. In this example, the matcher 630 may change thephysical shape of the matcher 630 based on a control signal generated bythe controller. For example, the distance h between the conductor 631 ofthe matcher 630 and the ground conducting portion 613 may increase ordecrease based on the control signal. Accordingly, the physical shape ofthe matcher 630 may be changed and the impedance of the resonator 600may be adjusted. The controller may generate the control signal based onvarious factors, which is further described later.

As shown in FIG. 6, the matcher 630 may be a passive element such as theconductor 631. As another example, the matcher 630 may be an activeelement such as a diode, a transistor, and the like. When the activeelement is included in the matcher 630, the active element may be drivenbased on the control signal generated by the controller, and theimpedance of the resonator 600 may be adjusted based on the controlsignal. For example, a diode that is a type of active element may beincluded in the matcher 630. The impedance of the resonator 600 may beadjusted depending on whether the diode is in an on state or in an offstate.

Although not illustrated in FIG. 6, a magnetic core may pass through theMNG resonator 600. The magnetic core may increase the power transmissiondistance.

FIG. 7 illustrates a three-dimensional (3D) example of a resonator.

Referring to FIG. 7, resonator 700 includes a transmission line and acapacitor 720. In this example, the transmission line includes a firstsignal conducting portion 711, a second signal conducting portion 712,and a ground conducting portion 713. The capacitor 720 may be insertedin series between the first signal conducting portion 711 and the secondsignal conducting portion 712 of the transmission line, and an electricfield may be confined within the capacitor 720.

In this example, the transmission line includes the first signalconducting portion 711 and the second signal conducting portion 712 inan upper portion of the resonator 700, and includes the groundconducting portion 713 in a lower portion of the resonator 700. Forexample, the first signal conducting portion 711 and the second signalconducting portion 712 may be disposed such that they face the groundconducting portion 713. Current may flow in an x direction through thefirst signal conducting portion 711 and the second signal conductingportion 712. As a result of the current, a magnetic field H(W) may beformed in a −y direction. Alternatively, unlike the diagram of FIG. 7,the magnetic field H(W) may be formed in a +y direction.

One end of the first signal conducting portion 711 may be shorted to aconductor 742, and another end of the first signal conducting portion711 may be connected to the capacitor 720. One end of the second signalconducting portion 712 may be grounded to a conductor 741, and anotherend of the second signal conducting portion 712 may be connected to thecapacitor 720. Accordingly, the first signal conducting portion 711, thesecond signal conducting portion 712, the ground conducting portion 713,and the conductors 741 and 742 may be connected to each other such thatthe resonator 700 has an electrically closed-loop structure, asdescribed with reference to FIG. 6.

As shown in FIG. 7, the capacitor 720 may be inserted between the firstsignal conducting portion 711 and the second signal conducting portion712. For example, the capacitor 720 may be inserted into a space betweenthe first signal conducting portion 711 and the second signal conductingportion 712. The capacitor 720 may have various shapes, for example, ashape of a lumped element, a distributed element, and the like. Forexample, a distributed capacitor that has the shape of the distributedelement may include zigzagged conductor lines and a dielectric materialthat has a relatively high permittivity between the zigzagged conductorlines.

As the capacitor 720 is inserted into the transmission line, theresonator 700 may have a property of a metamaterial.

When a capacitance of the capacitor inserted as the lumped element isappropriately determined, the resonator 700 may have the characteristicof the metamaterial. Because the resonator 700 may have a negativemagnetic permeability by adjusting the capacitance of the capacitor 720,the resonator 700 may also be referred to as an MNG resonator. Variouscriteria may be applied to determine the capacitance of the capacitor720. For example, the various criteria may include a criterion forenabling the resonator 700 to have the characteristic of themetamaterial, a criterion for enabling the resonator 700 to have anegative magnetic permeability in a target frequency, a criterionenabling the resonator 700 to have a zeroth order resonancecharacteristic in the target frequency, and the like. The capacitance ofthe capacitor 720 may be determined based on one or more criterion.

The resonator 700, also referred to as the MNG resonator 700, may have azeroth order resonance characteristic that has, as a resonancefrequency, a frequency when a propagation constant is “0”. Because theresonator 700 may have the zeroth order resonance characteristic, theresonance frequency may be independent with respect to a physical sizeof the MNG resonator 700. By appropriately designing the capacitor 720,the MNG resonator 700 may sufficiently change the resonance frequency.Accordingly, the physical size of the MNG resonator 700 may not bechanged.

Referring to the MNG resonator 700 of FIG. 7, in a near field, theelectric field may be concentrated on the capacitor 720 inserted intothe transmission line. Accordingly, due to the capacitor 720, themagnetic field may become dominant in the near field. For example,because the MNG resonator 700 having the zeroth-order resonancecharacteristic may have characteristics similar to a magnetic dipole,the magnetic field may become dominant in the near field. A relativelysmall amount of the electric field formed due to the insertion of thecapacitor 720 may be concentrated on the capacitor 720 and thus, themagnetic field may become further dominant.

Also, the MNG resonator 700 may include a matcher 730 for impedancematching. The matcher 730 may adjust the strength of magnetic field ofthe MNG resonator 700. An impedance of the MNG resonator 700 may bedetermined by the matcher 730. For example, current may flow into and/orout of the MNG resonator 700 via a connector 740. The connector 740 maybe connected to the ground conducting portion 713 or the matcher 730.

For example, as shown in FIG. 7, the matcher 730 may be positionedwithin the loop formed by the loop structure of the resonator 700. Thematcher 730 may adjust the impedance of the resonator 700 by changingthe physical shape of the matcher 730. For example, the matcher 730 mayinclude a conductor 731 for the impedance matching in a location that isseparated from the ground conducting portion 713 by a distance h.Accordingly, the impedance of the resonator 700 may be changed byadjusting the distance h.

Although not illustrated in FIG. 7, a controller may be provided tocontrol the matcher 730. In this example, the matcher 730 may change thephysical shape of the matcher 730 based on a control signal generated bythe controller. For example, the distance h between the conductor 731 ofthe matcher 730 and the ground conducting portion 713 may increase ordecrease based on the control signal. Accordingly, the physical shape ofthe matcher 730 may be changed and the impedance of the resonator 700may be adjusted.

The distance h between the conductor 731 of the matcher 730 and theground conducting portion 713 may be adjusted using a variety ofschemes. For example, a plurality of conductors may be included in thematcher 730 and the distance h may be adjusted by adaptively activatingone of the conductors. As another example, the distance h may beadjusted by adjusting the physical location of the conductor 731 up anddown. The distance h may be controlled based on the control signal ofthe controller. For example, controller may generate the control signalusing various factors. An example of the controller generating thecontrol signal will be described later.

As shown in FIG. 7, the matcher 730 may be a passive element such as theconductor 731. As another example, the matcher 730 may be an activeelement such as a diode, a transistor, and the like. When the activeelement is included in the matcher 730, the active element may be drivenbased on the control signal generated by the controller, and theimpedance of the resonator 700 may be adjusted based on the controlsignal. For example, a diode that is a type of active element may beincluded in the matcher 730. The impedance of the resonator 700 may beadjusted depending on whether the diode is in an on state or in an offstate.

Although not illustrated in FIG. 7, a magnetic core may pass through theresonator 700 configured as the MNG resonator. The magnetic core mayincrease the power transmission distance.

FIG. 8 illustrates an example of a resonator for wireless powertransmission configured as a bulky type.

Referring to FIG. 8, a first signal conducting portion 811 and a secondsignal conducting portion 812 may be integrally formed instead of beingseparately manufactured and later connected to each other. Similarly,the second signal conducting portion 812 and a conductor 841 may also beintegrally manufactured.

When the second signal conducting portion 812 and the conductor 841 areseparately manufactured and subsequently connected to each other, a lossof conduction may occur due to a seam 850. The second signal conductingportion 812 and the conductor 841 may be connected to each other withoutusing a separate seam such that they are seamlessly connected to eachother. Accordingly, it is possible to decrease a conductor loss causedby the seam 850. Accordingly, the second signal conducting portion 812and a ground conducting portion 813 may be seamlessly and integrallymanufactured. Similarly, the first signal conducting portion 811 and theground conducting portion 813 may be seamlessly and integrallymanufactured.

Referring to FIG. 8, a type of a seamless connection connecting at leasttwo partitions into an integrated form is referred to as a bulky type.

FIG. 9 illustrates an example of a resonator for wireless powertransmission configured as a hollow type.

Referring to FIG. 9, each of a first signal conducting portion 911, asecond signal conducting portion 912, a ground conducting portion 913,and conductors 941 and 942 of the resonator 900 configured as the hollowtype include an empty space inside.

In a given resonance frequency, an active current may be modeled to flowin only a portion of the first signal conducting portion 911 instead ofthe entire first signal conducting portion 911, only a portion of thesecond signal conducting portion 912 instead of the entire second signalconducting portion 912, only a portion of the ground conducting portion913 instead of the entire ground conducting portion 913, and only aportion of the conductors 941 and 942 instead of the entire conductors941 and 942. For example, when a depth of each of the first signalconducting portion 911, the second signal conducting portion 912, theground conducting portion 913, and the conductors 941 and 942 issignificantly deeper than a corresponding skin depth in the givenresonance frequency, it may be ineffective. The significantly deeperdepth may increase a weight or manufacturing costs of the resonator 900.

Accordingly, in the given resonance frequency, the depth of each of thefirst signal conducting portion 911, the second signal conductingportion 912, the ground conducting portion 913, and the conductors 941and 942 may be appropriately determined based on the corresponding skindepth of each of the first signal conducting portion 911, the secondsignal conducting portion 912, the ground conducting portion 913, andthe conductors 941 and 942. When the first signal conducting portion911, the second signal conducting portion 912, the ground conductingportion 913, and the conductors 941 and 942 have an appropriate depththat is deeper than a corresponding skin depth, the resonator 900 maybecome light, and manufacturing costs of the resonator 900 may alsodecrease.

For example, as shown in FIG. 9, the depth of the second signalconducting portion 912 may be determined as “d” mm and d may bedetermined according to

$d = {\frac{1}{\sqrt{\pi \; f\; \mu \; \sigma}}.}$

In this example, f denotes a frequency, μ denotes a magneticpermeability, and σ denotes a conductor constant.

For example, if the first signal conducting portion 911, the secondsignal conducting portion 912, the ground conducting portion 913, andthe conductors 941 and 942 are made of a copper and have a conductivityof 5.8×10⁷ siemens per meter (S·m⁻¹), the skin depth may be about 0.6 mmwith respect to 10 kHz of the resonance frequency and the skin depth maybe about 0.006 mm with respect to 100 MHz of the resonance frequency.

FIG. 10 illustrates an example of a resonator for a wireless powertransmission using a parallel-sheet.

Referring to FIG. 10, the parallel-sheet may be applicable to each of afirst signal conducting portion 1011 and a second signal conductingportion 1012 included in the resonator 1000.

For example, each of the first signal conducting portion 1011 and thesecond signal conducting portion 1012 may not be a perfect conductor,and thus, may have a resistance. Due to the resistance, an ohmic lossmay occur. The ohmic loss may decrease a Q-factor and may also decreasea coupling effect.

By applying the parallel-sheet to each of the first signal conductingportion 1011 and the second signal conducting portion 1012, it ispossible to decrease the ohmic loss, and to increase the Q-factor andthe coupling effect. For example, referring to a portion 1070 indicatedby a circle, when the parallel-sheet is applied, each of the firstsignal conducting portion 1011 and the second signal conducting portion1012 may include a plurality of conductor lines. For example, theplurality of conductor lines may be disposed in parallel, and may beshorted at an end portion of each of the first signal conducting portion1011 and the second signal conducting portion 1012.

As described above, when the parallel-sheet is applied to each of thefirst signal conducting portion 1011 and the second signal conductingportion 1012, the plurality of conductor lines may be disposed inparallel. Accordingly, a sum of resistances having the conductor linesmay decrease. As a result, the resistance loss may decrease, and theQ-factor and the coupling effect may increase.

FIG. 11 illustrates an example of a resonator for a wireless powertransmission that includes a distributed capacitor.

Referring to FIG. 11, a capacitor 1120 included in the resonator 1100for the wireless power transmission may be a distributed capacitor. Acapacitor as a lumped element may have a relatively high equivalentseries resistance (ESR). A variety of schemes have been proposed todecrease the ESR contained in the capacitor of the lumped element. Forexample, by using the capacitor 1120 as a distributed element, it ispossible to decrease the ESR. A loss caused by the ESR may decrease aQ-factor and a coupling effect.

As shown in FIG. 11, the capacitor 1120 as the distributed element mayhave a zigzagged structure. For example, the capacitor 1120 as thedistributed element may be configured as a conductive line and aconductor having the zigzagged structure.

As shown in FIG. 11, by employing the capacitor 1120 as the distributedelement, it is possible to decrease the loss that occurs due to the ESR.In addition, by disposing a plurality of capacitors as lumped elements,it is possible to decrease the loss that occurs due to the ESR. Becausea resistance of each of the capacitors as the lumped elements decreasesthrough a parallel connection, active resistances of parallel-connectedcapacitors as the lumped elements may also decrease and the loss thatoccurs due to the ESR may decrease. For example, by employing tencapacitors of 1 pF instead of using a single capacitor of 10 pF, it ispossible to decrease the loss occurring due to the ESR.

FIG. 12A illustrates an example of the matcher 630 used in the resonator600 of FIG. 6, and FIG. 12B illustrates an example of the matcher 730used in the resonator 700 of FIG. 7.

FIG. 12A illustrates a portion of the resonator including the matcher630, and FIG. 12B illustrates a portion of the resonator including thematcher 730.

Referring to FIG. 12A, the matcher 630 includes a conductor 631, aconductor 632, and a conductor 633. The conductors 632 and 633 may beconnected to the ground conducting portion 613 and the conductor 631.The impedance of the 2D resonator may be determined based on a distanceh between the conductor 631 and the ground conducting portion 613. Thedistance h between the conductor 631 and the ground conducting portion613 may be controlled by the controller. For example, the distance hbetween the conductor 631 and the ground conducting portion 613 may beadjusted using a variety of schemes. For example, the variety of schemesmay include a scheme of adjusting the distance h by adaptivelyactivating one of the conductors 631, 632, and 633, a scheme ofadjusting the physical location of the conductor 631 up and down, andthe like.

Referring to FIG. 12B, the matcher 730 includes a conductor 731, aconductor 732, and a conductor 733. The conductors 732 and 733 may beconnected to the ground conducting portion 713 and the conductor 731.The conductors 732 and 733 may be connected to the ground conductingportion 713 and the conductor 731. The impedance of the 3D resonator maybe determined based on a distance h between the conductor 731 and theground conducting portion 713. For example, the distance h between theconductor 731 and the ground conducting portion 713 may be controlled bythe controller. Similar to the matcher 630 included in the 2D resonatorillustration, in the matcher 730 included in the 3D resonatorillustration, the distance h between the conductor 731 and the groundconducting portion 713 may be adjusted using a variety of schemes. Forexample, the variety of schemes may include a scheme of adjusting thedistance h by adaptively activating one of the conductors 731, 732, and733, a scheme of adjusting the physical location of the conductor 731 upand down, and the like.

Although not illustrated in FIGS. 12A and 12B, the matcher may includean active element. A scheme of adjusting an impedance of a resonatorusing the active element may be similar as described above. For example,the impedance of the resonator may be adjusted by changing a path ofcurrent flowing through the matcher using the active element.

FIG. 13 illustrates an example of an equivalent circuit of the resonator600 for wireless power transmission of FIG. 6.

The resonator 600 for the wireless power transmission may be modeled tothe equivalent circuit of FIG. 13. In the equivalent circuit of FIG. 13,C_(L) denotes a capacitor that is inserted in a form of a lumped elementin the middle of the transmission line of FIG. 6.

In this example, the resonator 600 may have a zeroth resonancecharacteristic. For example, when a propagation constant is “0”, theresonator 600 may be assumed to have ω_(MZR) as a resonance frequency.The resonance frequency ω_(MZR) may be expressed by Equation 2.

$\begin{matrix}{\omega_{MZR} = \frac{1}{\sqrt{L_{R}C_{L}}}} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$

In Equation 2, MZR denotes a Mu zero resonator.

Referring to Equation 2, the resonance frequency ω_(MZR) of theresonator 600 may be determined by L_(R)/C_(L). A physical size of theresonator 600 and the resonance frequency ω_(MZR) may be independentwith respect to each other. Because the physical sizes are independentwith respect to each other, the physical size of the resonator 600 maybe sufficiently reduced.

The processes, functions, methods, and/or software described herein maybe recorded, stored, or fixed in one or more computer-readable storagemedia that includes program instructions to be implemented by a computerto cause a processor to execute or perform the program instructions. Themedia may also include, alone or in combination with the programinstructions, data files, data structures, and the like. The media andprogram instructions may be those specially designed and constructed, orthey may be of the kind well-known and available to those having skillin the computer software arts. Examples of computer-readable storagemedia include magnetic media, such as hard disks, floppy disks, andmagnetic tape; optical media such as CD ROM disks and DVDs;magneto-optical media, such as optical disks; and hardware devices thatare specially configured to store and perform program instructions, suchas read-only memory (ROM), random access memory (RAM), flash memory, andthe like. Examples of program instructions include machine code, such asproduced by a compiler, and files containing higher level code that maybe executed by the computer using an interpreter. The described hardwaredevices may be configured to act as one or more software modules thatare recorded, stored, or fixed in one or more computer-readable storagemedia, in order to perform the operations and methods described above,or vice versa. In addition, a computer-readable storage medium may bedistributed among computer systems connected through a network andcomputer-readable codes or program instructions may be stored andexecuted in a decentralized manner.

As a non-exhaustive illustration only, the terminal device describedherein may refer to mobile devices such as a cellular phone, a personaldigital assistant (PDA), a digital camera, a portable game console, anMP3 player, a portable/personal multimedia player (PMP), a handhelde-book, a portable lab-top personal computer (PC), a global positioningsystem (GPS) navigation, and devices such as a desktop PC, a highdefinition television (HDTV), an optical disc player, a setup box, andthe like, capable of wireless communication or network communicationconsistent with that disclosed herein.

A computing system or a computer may include a microprocessor that iselectrically connected with a bus, a user interface, and a memorycontroller. It may further include a flash memory device. The flashmemory device may store N-bit data via the memory controller. The N-bitdata is processed or will be processed by the microprocessor and N maybe 1 or an integer greater than 1. Where the computing system orcomputer is a mobile apparatus, a battery may be additionally providedto supply operation voltage of the computing system or computer.

It should be apparent to those of ordinary skill in the art that thecomputing system or computer may further include an application chipset,a camera image processor (CIS), a mobile Dynamic Random Access Memory(DRAM), and the like. The memory controller and the flash memory devicemay constitute a solid state drive/disk (SSD) that uses a non-volatilememory to store data.

A number of example embodiments have been described above. Nevertheless,it should be understood that various modifications may be made. Forexample, suitable results may be achieved if the described techniquesare performed in a different order and/or if components in a describedsystem, architecture, device, or circuit are combined in a differentmanner and/or replaced or supplemented by other components or theirequivalents. Accordingly, other implementations are within the scope ofthe following claims.

What is claimed is:
 1. A radiative wireless power transmitter,comprising: a plurality of unit resonators configured to transmit aresonance power to target device; a plurality of matchers configured toenable the plurality of unit resonators to form a magnetic field with atleast one target resonator of the target device; and a feeding unitconfigured to determine a transmission direction of the resonance powerbased on control of at least one of the plurality of matchers.
 2. Theradiative wireless power transmitter of claim 1, wherein the pluralityof unit resonators comprises: first unit resonators configured to form amagnetic field with the target resonator based on an x-axis directionand a z-axis direction; second unit resonators configured to form amagnetic field with the target resonator based on the x-axis directionand a y-axis direction; and third unit resonators configured to form amagnetic field with the target resonator based on the y-axis directionand the z-axis direction.
 3. The radiative wireless power transmitter ofclaim 1, wherein one of the plurality of unit resonators is parallelwith one of XY plane, YZ plane, and ZX plane.
 4. The radiative wirelesspower transmitter of claim 1, wherein the feeding unit controls the atleast one of the plurality of matchers to form a magnetic field in apredetermined direction.
 5. The radiative wireless power transmitter ofclaim 1, wherein the feeding unit control of at least one of theplurality of matchers to enable the at least one of the plurality ofunit resonators to transmit the resonance power to target resonator thatfaces the at least one of the plurality of unit resonators.
 6. Theradiative wireless power transmitter of claim 1, wherein at least one ofthe plurality of matchers is placed in a plane that is parallel with atleast one of the plurality of unit resonators.
 7. The radiative wirelesspower transmitter of claim 1, wherein at least one of the plurality ofunit resonators comprises: a transmission line that comprises a firstsignal conducting portion, a second signal conducting portion, and aground conducting portion corresponding to the first signal conductingportion and the second signal conducting portion; a first conductor thatis electrically connected to the first signal conducting portion and theground conducting portion; a second conductor that is electricallyconnected to the second signal conducting portion and the groundconducting portion; and at least one capacitor inserted between thefirst signal conducting portion and the second signal conducting portionin series with respect to a current flowing through the first signalconducting porting and the second signal conducting portion.
 8. Theradiative wireless power transmitter of claim 1, further comprising: acontroller configured to control impedances of the a plurality of unitresonators.
 9. A radiative wireless power receiver, comprising: aplurality of unit resonators configured to receive a resonance powerfrom source device; and a feeding unit configured to control at leastone of a plurality of matcher to enable wireless power reception to beperformed in a predetermined direction.
 10. The radiative wireless powerreceiver of claim 9, wherein the plurality of unit resonators comprise:first unit resonators configured to form a magnetic field with a sourceresonator based on an x-axis direction and z-axis direction; second unitresonators configured to form a magnetic field with the source resonatorbased on the x-axis direction and a y-axis direction; third unitresonators configured to form a magnetic field with the source resonatorbased on the y-axis direction and the z-axis direction.
 11. Theradiative wireless power receiver of claim 9, further comprising: adetector configured to detect at least one of a distance between awireless power transmission resonator and a wireless power receptionresonator, a reflection coefficient of a wave emitted from the wirelesspower transmission resonator to the wireless power reception resonator,a power transmission gain between the wireless power transmissionresonator and the wireless power reception resonator, and a couplingefficiency.